M-1 5/30 and oil light coming on. Advice please.

[DSteven]

This has happened three times on three different cars with the same Mitsubishi engine. On the last Stratus 2.5L 24V V6, when I switched to Mobil-1, after driving and coming to idle the oil light came on. The engine had nearly 170000 miles, but very well maintained. Shortly after, it was smashed. I replaced it with a 97 that has 74000 miles now, it also did the same thing when switched to M1 5w30, as well as the 97 Cirrus with 120000 miles. The engines are all the same Mitsubishi 2.5L 24V V6, which show VERY good wear numbers and long life. The manual calls for 5w30 oil; however, the best wear rates seem to be with a 10w30 MaxLife and Castrol 10w30. The engines have used various 5w30 oils, with no issues. Just the M1 has given the oil light troubles. Any input? I like the 5w30 for better startup protection in MN and better MPG. Any input as to why the M1 does this? I thought M15/30 actually was thicker at operating temp than the M1 10w30. Should these engines stay with the MaxLife (overpriced group 3) synthetic? Any input on the matter?

 

[DJ]

From my reading here and specifically research on the engine in my car the M1 30wts. are just too thin for some applications. My car is a 96 Caprice with LT1 and GM speced M1 5w30 for the Vettes with this motor, but UOAs show it to be a less than wonderful choice. Since it is just this oil you have had trouble with I would guess yours is a similar problem. The popular option for the LT1 is to switch to M1 0w-40 or 5w-40, maybe see if anyone has used those in your engine. You could get as good as or better cold weather protection without the hot oil light troubles.

This is just anecdotal but on the Camaro board some spun bearing have been popping up, now granted these are cars driven hard but it almost seems like it is the guys who thought they were doing the best for their car by using M1 5w30(because speced for the Vette with same motor) that are having trouble. It does perform very well in some motors just not all that spec 5w30 in the manual.

 

[SEBZX79]

It is not the oil, its the oil sending unit.
The oil light flickers at idle only. I have a 2k Cirrus with the 2.5 and I replaced the Oil sending unit which is like 12 dollars it is located right next to the oil filter. Next time you change your oild change the oil sending unit out and you will be fine. It is all of 2 min of work and it fixes the problem.
This same problem happens on a 2.7 liter also that uses the same sending unit.

By the way I use Mobil 1 0w40 with 8-10k OCI. Good engine but bad on gas.

Good luck
Sebastian

 

[DSteven]

Thanks for the information. It was the oil pressure sending unit! At least it's an easy repair! How long could one project these engines to run, with good maintenence? 200,000...maybe 300,000? How about M1, spiked with 1qt of RedLine 5w30 and 5000M OCI?